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An attempt is made to critically study the measuring urbanisation, recent urban growth patterns, Urban Growth Sustainability (UGS) and addresses the question of how the primate city impacts urban growth. The methods of Urban-Rural Growth Differential (URGD), Composite Annual Growth Rate (CAGR) and Index of Primacy (PI) have been used to understand recent urban growth, impact of primate cities in India based on Census. The top-heavy nature of India's metropolitan structure has a negative impact on the country's balanced regional growth. The study recommends that more infrastructure capacity should be granted for the primate cities due to increases in the city's population. [ABSTRACT FROM AUTHOR]

Effectively monitoring the size of a city in real time enables the scientific planning of urban development. Models that utilize the distribution and variations in city size generally use population data as inputs, which cannot be obtained in a timely and rapid manner. However, night-time light (NTL) remote sensing may be an alternative method. A case study was carried out on the Yangtze River Delta (YRD) in China, and the rank–size rule, the law of primate cities, and the Gini coefficient were employed to monitor the variation in city size in the study area. The urban areas extracted based on NTL remote sensing were utilized instead of the traditionally used population data to evaluate the variations in city size from 2012 to 2017. Considering the empiricism and subjectivity of the thresholding method, urban areas were extracted from NTL data combined with the normalized differential vegetation index and land-surface temperature data based on the artificial neural network algorithm. Based on the results, the YRD did not fit the distribution of the primate cities from 2012 to 2017. However, this region satisfied the rank–size rule well, which indicated that the development of medium–small cities was more prominent than that of larger cities, and the dispersed force was larger than the concentrated force. Notably, the city size reached a relatively balanced level in the study area. Further, sensitivity analysis revealed that the relatively low extraction accuracy of urban areas of few small cities had little effect on the results of city size variations. Moreover, the validation of city size computed from statistical population data and its comparison with results calculated based on the statistical data of urban areas aligned with the results of this study, which indicates the rationality and applicability of monitoring the variations in city size using the urban areas extracted from NTL remote sensing instead of population data. [ABSTRACT FROM AUTHOR]

Objectives: As the acceleration of global urbanization, traffic congestion and environmental degradation have emerged in the urban area. Based on the light and statistical data, this paper studied the spatial evolution between urban people and land, and revealed the significance of its coupling and coordination characteristics for the sustainable development of cities. Methods: For primary data, a series of preprocessing are needed to eliminate the problems of supersaturation and discontinuity of inter‑annual data. Based on the lighting threshold, this paper excerpted the built‑up areas of urban agglomeration in Zhejiang Province year by year, compared them with the statistical data, and analyzed the corrected data source relatively. Firstly, based on the order‑scale distribution model of urban order and urban population in Zhejiang Province from 1992 to 2020, we made a dynamic analysis on population aggregation and distribution in its development process. Then, we constructed the population‑land urbanization allometric growth model by using population and light area, as well as judged the spatialization of man‑land relationship in urban development. Finally, according to the lag phenomenon of population growth relative to land development, we proposed an allometric growth model with lag factor, and used the lag term model to judge the characteristics of unequal growth of people and land in different cities. Results: The structural system of urban agglomeration is relatively mature in Zhejiang Province, and the distribution of cities is reasonable. However, the primacy of city is gradually improved, and the population is gradually gathering. The results of allometric growth model show that the man‑land relationship of urban agglomeration in Zhejiang Province is generally low in the eastern coastal cities and high in the western inland cities, and the planning of the four metropolitan areas is reasonable. The improvement of fitting accuracy of the proposed model with lag factor obviously shows that there is lag effect between population urbanization and land urbanization, with an average increase of 6.47% and the highest increase of 12.61%. Among the influencing factors on land urbanization, the dominant factor in Hangzhou is the existing population in urban areas, while the dominant factor in Ningbo is the new population in urban areas. Conclusions: The proposed allometric growth model with lag factor can correct the model errors and improve the fitting accuracy of urban man‑land relationship. It can also effectively evaluate the temporal and spatial evolution characteristics of man‑land relationship in regional system, explore its development and put forward countermeasures. [ABSTRACT FROM AUTHOR]

We present a comprehensive agent-based model of a closed system of cities. The model includes two types of agents—employees and firms. Firms compete for workers and make decisions concerning what to produce and whether to adopt innovations. Individual employees make migration decisions. Some migrants become intrapreneurs when their employers adopt production process innovations that they propose. Some migrants become entrepreneurs when the product innovations that they propose are implemented by their employers in new subsidiary firms. These firms tend to be technological leaders. The decisions of individuals and of firms generate innovation–migration dynamics that generate a variety of city sizes. A city that is home to firms that are currently relatively attractive to migrating innovators experience moderate or fast growth. Because of particular decision patterns by individuals and firms, this growth may decline and stop, and the city may stagnate and loose workers as its relative attractiveness decreases. Cities that remain unattractive for long periods can stop growing and shrink. We model explicitly the extent to which cities attract immigrants and innovators and demonstrate that the size distribution of cities is defined by the ability of its resident firms to adopt the innovations and to let the product innovators establish technologically advanced enterprises. These decisions result in high market value of the most productive firms, of the entire industrial system the city where the firm is located, and of the entire urban system. [ABSTRACT FROM AUTHOR]

Megaregions have become the principal geographic units for countries to participate in the global economy, which is often a composite of numerous urban clusters which are distributed in different cities. In China, a megaregion is regarded as a key urbanization platform, according to the National Plan on New Urbanization published in 2014. In this context, it is imperative to understand the spatial patterns of and the changes occurring in megaregions. For instance, what are the universal rules or differences related to urban cluster growth between different megaregions in the process of rapid urbanization, and are there differences in the growth of urban clusters with different sizes? Focusing on these issues, this study discusses the uneven growth of clusters in five of the largest megaregions in China using the rank-size rule, based on land-cover data interpreted from time-series satellite imagery during the period 1990–2010. The results show that the cluster size distribution of each of these megaregions obeyed the rank-size rule, and the size distribution of the clusters became more uneven and was tilted toward larger clusters between 1990 and 2010. These factors should be considered in the implementation of the National Plan on New Urbanization in China and the designation of urban macro planning and urban layout optimization in other countries those are experiencing rapid urbanization. [ABSTRACT FROM AUTHOR]

The salient rank–size rule for city sizes known as ‘Zipf’s law’ is not only satisfied for Germany's national urban hierarchy, but also in single German regions. To analyse this phenomenon, we build on the theory by Gabaix (1999 Quarterly Journal of Economics, 94:739–767) that Zipf's law follows (under certain conditions) from a stochastic urban growth process. In particular, Gabaix shows that if urban growth in all regions follows Gibrat's law, we should observe the Zipfian rank-size rule among large cities both at the regional and national level. This theory has never been addressed empirically. Using non-parametric techniques and various definitions of a ‘region’, we find that Gibrat's law holds at the regional level. Consistently, we find that city size distributions at the national and regional levels tend to follow a Zipfian power law. [ABSTRACT FROM PUBLISHER]

In recent years, much research has been devoted to developing appropriate analytical frameworks to capture polycentric urban development (PUD). In a recent contribution to this journal, Bartosiewicz and Marcińczak (2020) present what is arguably the most comprehensive, comparative review to date of the degree to which different analytical frameworks produce consistent results. The purpose of this research note is to show why we believe parts of Bartosiewicz and Marcińczak's (2020) findings need nuance and qualification. Our starting point is that a useful comparison between different studies and measurement frameworks needs to consider the relevance of consistency in several key dimensions, two of which are particularly pertinent here: (1) the careful specification of what constitutes a 'center' in a polycentric urban system, and (2) the identification of the 'balance' between centers as a measure of the degree of polycentricity. Two brief empirical analyses of the degree of morphological polycentricity in Polish NUTS-3 areas and the Chinese city-regions along the 'Yangtze Economic Belt' are included. Finally, suggestions are provided to facilitate future comparative analyses of PUD. • Appropriate definitions of 'centers' and 'balance' are critical for measuring polycentric urban development (PUD). • Mutually comparable treatments of 'centers' and 'balance' are needed for comparative analyses of PUD. • Center definition should reflect the conceptual focus on PUD. • Geographical context and design of indicators matter when engaging in comparative analyses of PUD. • Providing multiple indicators is useful in comparative analyses of PUD. [ABSTRACT FROM AUTHOR]

Urban sprawl is the most prominent characteristic of urbanization, and increasingly affects local and regional sustainable development. The observation and analysis of urban sprawl dynamics and their relationship with urbanization quality are essential for framing integrative urban planning. In this study, the urban areas of the West Taiwan Strait Urban Agglomeration (WTSUA) were extracted using nighttime light imagery from 1992 to 2013. The spatio-temporal characteristics and pattern of urban sprawl were quantitatively analyzed by combining an urban expansion rate index and a standard deviation ellipse model. The urbanization quality was assessed using an entropy weight model, and its relationship with urban sprawl was calculated by a coupling coordination degree model. The results showed that the urban area in the WTSUA experienced a significant increase, i.e., 18,806.73 km2, during the period 1992–2013. The central cities grew by 11.08% and noncentral cities by 27.43%, with a general uneven city rank-size distribution. The urban sprawl showed a circular expansion pattern, accompanied by a gradual centroid migration of urban areas from the southeast coast to the central-western regions. The coupling coordination level between urban expansion and urbanization quality increased from serious incoordination in 1992 to basic coordination in 2013. Dual driving forces involving state-led policies and market-oriented land reform had a positive influence on the harmonious development of urban sprawl and urbanization quality of the WTSUA. This research offers an effective approach to monitor changes in urban sprawl and explore the coupling coordination relationship between urban sprawl and urbanization quality. The study provides important scientific references for the formulation of future policies and planning for sustainable development in urban agglomerations. [ABSTRACT FROM AUTHOR]